Is it permissible to pray in congregation with a prior intention, then discover the invalidity of the ablution after the prayer due to the absence of water, knowing that the worshiper was ignorant of the religious ruling?

It is not permissible to transition from ablution (wudu') to dry ablution (tayammum) except due to illness where the use of water would be detrimental, or due to the lack of water. One is considered to have lost water if they have exerted effort in seeking it but did not find it. If one finds neither water nor pure earth (sa'id) and fears the expiration of the prayer time, they should pray in their current state, and there is no need for them to repeat the prayer, due to Allah's saying: (So fear Allah as much as you are able). However, if one prays without seeking water, or is negligent in seeking it, they must repeat the prayer as long as the time remains. If the time has expired, then there is no need for them to repeat the prayer.